Mechanical cardiac assist pump devices have increasingly been used to maintain blood circulation and supply oxygen to organs and body tissue during a cardiopulmonary bypass procedure or where the natural heart is otherwise incapable of functioning as desired.
Such cardiopulmonary bypass pumps are typically centrifugal or roller (i.e., peristaltic) pump designs. Such designs provide advantages of simplicity of operation, reliability, and relatively low cost. One particular disadvantage of roller pump designs is blood damage (e.g., red blood cell damage and platelet activation) that can occur, and particulate spallation, a condition in which particulates from the tubing or pump components break off, contaminating the blood. As a result, the use of roller pumps can be generally limited to no more than about 4 hours.
Centrifugal pumps have increasingly been used as blood pumps. Such centrifugal pumps tend to exhibit lower incidence of blood damage, absence of spallation, and their use may be extended for periods of up to several days, if needed. However, the size of both roller pump and centrifugal pump configurations tend to be fairly large.
Therefore, manufacturers and users of blood pumps continue to seek improved blood pumps.